compare them here using model numbers https://ruger.com/products/pcCarbine/models.html

Hi Burt, without knowing exact model you are talking about, hard to give a definite answer. They all come with 16.1" barrels and they are all 9mm. The different PC Carbines can be seen here >>> ruger.com/products/pcCarbine/models.html
Stay safe & have a great day!

Burt, depends exactly Wich model you're talking about, Ruger makes quite a few different ones. If you post with either the model number or upc of both can give a definite answer. The core rifles of all the PC carbines are the same. Only difference is some have different finish/color, different stocks/handguard, some come with state compliant 10 round magazines instead of standard capacity. Again you can find the model number and upc under the products description then we can give a definite answer. Hope this helps some.

Hi Burt and welcome. Just a difference in handguard/Stocks. The core carbine is the same. Cheers and stay safe!